Hydatid disease, or cystic echinococcosis, is a parasitic infection caused by a tapeworm. It can cause cysts to grow in your liver and other organs. The infection is common in rural, underdeveloped areas where people raise livestock. Hydatid disease is rare in North America.
Hydatid disease is a parasitic infection caused by a tapeworm’s eggs. Tapeworms usually live in hosts such as sheep and dogs. But humans can get the disease if they accidentally eat or drink anything infected with the parasite. Hydatid disease is rare in North America.
Hydatid disease, also called cystic echinococcosis or hydatidosis, causes cysts (liquid-filled growths) to develop in your liver or other organs. Hydatid cysts can lead to serious health complications if they aren’t treated.
Hydatid disease tends to occur in rural, poor or underdeveloped areas. It’s especially common among people who raise sheep or other livestock and also have dogs. Sheep are the primary host of the parasite and dogs get the parasite when they eat an infected sheep.
The risk of hydatid disease increases if you:
Hydatid disease isn’t contagious, meaning it doesn’t spread through person-to-person contact. So you can’t get the disease by touching or being near someone who has it. A person has to ingest the parasite to get the infection.
Alveolar echinococcosis (AE) is another type of parasitic infection caused by tapeworms in the genus Echinocococcus. But AE is usually transmitted to humans through foxes and coyotes, not sheep. AE is more serious than cystic echinococcosis (CE). AE can lead to cysts in your liver, lungs and brain. The cysts aren’t cancerous but spread similarly to invasive tumors.
A hydatid cyst is the result of a parasitic infection. Simple liver cysts, on the other hand, are usually present at birth. Hydatid cysts can grow large enough to affect liver function. Simple liver cysts rarely get this big. Hydatid cysts and simple liver cysts also require different treatments.
Hydatid disease isn’t common in North America. But it’s a growing public health concern in poor and rural areas of Africa, Europe, Asia, the Middle East and Central and South America. Between 2 million and 3 million human echinococcal infections occur each year worldwide, and hydatid disease accounts for about 95% of those infections.
Hydatid disease may not cause any symptoms for many years. But as hydatid cysts grow in your liver, lungs or other organs they may cause:
The cysts can grow large enough to prevent affected organs from working properly. The cysts can also rupture, which can lead to life-threatening complications. Signs of a ruptured hydatid cyst may include:
People can get hydatid disease if they come into contact with the feces (poop) of a dog that contains the parasite’s eggs. Over time, the parasites grow larger and turn into a cyst. Transmission can happen through:
Imaging exams and blood tests are the most common ways to diagnose hydatid disease. Blood tests can show elevated levels of antibodies to the echinococcal infection. Imaging exams show the size, shape and location of the cysts.
Your healthcare provider will use an X-ray, CT scan or ultrasound to examine the cysts. Hydatid cysts have a few characteristics that make them appear differently than simple liver cysts in imaging scans, including:
Treatment for hydatid disease depends on the size and location of the cysts. The most common treatments include:
Preventing the spread of parasites is the only way to control hydatid disease. People at risk of contracting the infection should:
Untreated hydatid disease can be fatal. Cysts may get so large that they cause the affected organ to stop functioning completely. Ruptured cysts can cause anaphylaxis, which is a life-threatening allergic reaction.
If you experience any of the symptoms of hydatid disease, see your healthcare provider right away. Tell them if you’ve been in a high-risk environment for hydatid disease. This information can help them distinguish between hydatid cysts and simple cysts. Early diagnosis and treatment greatly lower the risk of serious health complications or death.
A note from Cleveland Clinic
Hydatid disease, also called cystic echinococcosis, is a parasitic infection caused by a tapeworm. People can get the disease if they come into contact with dog feces containing the parasite. Hydatid disease causes cysts to grow in organs, usually your liver. Treatment involves medication, aspiration (cyst drainage) or surgery. Untreated hydatid disease can lead to serious health complications.
Last reviewed by a Cleveland Clinic medical professional on 07/28/2022.
Learn more about our editorial process.